Method for inducing anethesia

ABSTRACT

1-BROMO-1-CHLORO-2,3,3-TRIFLUOROPROPENE, USEFUL AS A GENERAL ANESTHETIC.

United States Patent Regan METHOD FOR INDUCING ANETHESIA inventor: Bernard M. Regan, Chicago, Ill.

Assignee: 'Baxter Laboratories, Inc., Morton Grove,

Ill.

Filed: June 29, 1970 Appl. No.: 60,179

Related US. Application Data Division of Ser. No. 699,060, Jan. 19, i968, Pat. No. 3,579,595.

[4 1 June 20, 1972 [56] References Cited UNITED STATES PATENTS 2,904,602 9/ l 95 9 llgenfritz ..260/ 65 3 .5 2,921,098 l/l960 Suckling ..260/653.5

Primary Examiner-Jerome D. Goldberg Attorney-Robert G. Pollock [57] ABSTRACT l-bromo-l-chloro-2,3,3-trifluoropropene, useful as a general anesthetic.

1 Claim, No Drawings METHOD FOR INDUCING ANETHESIA This is a division of application Ser. No. 699,060, filed Jan.

19, 1968, now U.S. Pat. No. 3,579,595.

The present invention relates to a novel fluorinated organic compound l-bromo-l-chloro-2,3,3-trifluoropropene, having the structure:

CBrCl CF -CHF More particularly, the present invention relates to the method of utilizing said compound as a general anesthetic for warmblooded, air-breathing animals.

Preparation of l-bromo-l-chloro-2,3,3-trifluoropropene is readily accomplished by dehydrofluorination of the corresponding halogenated propane having an additional central fluorine substituent at the point where the olefinic bond is desired.

in a preferred method of preparation of the novel fluorinated organic compound of this invention, l-bromo-lchloro-2,2,3, 3--tetrafluo ropropane is reacted with suitable alkaline material, for example, soda lime, at a temperature of from about 70 C to about 100 C. Substantial conversion to lbromo-l-chloro-2,3,3-trifluoro propene has been obtained by this method with reaction times of three hours or more. The novel compound of this invention can then be separated from its reaction components by fractional distillation.

The starting material in the above reaction, l-bromo-lchloro-2,2,3,3 tetrafluoropropane, is a known compound and has been described in U.S. Pat. No. 3,177,260.

l-bromo-1-ch1oro-2,3,3-trifluoropropene is a colorless liquid boiling at 965 C at 760 mm and is non-flammable in air or oxygen at ambient temperature. It is preferably stored in amber colored bottles in admixture with conventional stabilizer such as, for example, thymol. It can be administered by any conventional procedure or means suitable for administration of known general anesthetics to warm-blooded, airbreathing animals. The novel compound of this invention also is stable toward soda lime and, therefore, can be used in conventional re-circulation apparatus which employs soda lime for the absorption of carbon dioxide from the subject undergoing anesthesia.

The utility of the novel fluorinated organic compound of the present invention has been further demonstrated by its inhalation margin of safety in mice when compared with several conventional general anesthetics, namely, chloroform, ether and halothane.

The following example is set forth for purposes of further illustration of the present invention. All percentages herein are on a weight basis unless otherwise stated.

EX MP E 1-bromo-1-chloro-2,2,3,3-tetrafluoropropane (363 grams),

low moisture soda lime (180 grarns containing about 2;-

percent water) were heated to boiling under total reflux for 54 hours..GLC-analysis of the liquid reaction product showed it to be greater than 90 percent l-bromo-l-chloro- 2,3 ,Q-trifluoropropene. The yield of said product was 5 302 grams, which is 82 percent of theory.

Fractional distillation gave l-bromo-l-chloro-2,3,3-trifluoropropene, bm 96.0 C, d i 1.87 11 percent purity by GLC analysis. Its CBrCl CF-CHF structure was confirmed by proton nuclear magnetic resonance (NMR) and infrared spectra. mm

The physiological effects of l-bromo-l-chloro2,3,3-

3 trifluoropropene were demonstrated in white mice by subject ing the mice to various concentrations of said. compound vaporized in admixture with air in 6.3 dessicator jars with ten mice used for each concentration. The concentration of anesthetic vapor in admixture with air in the jar was calculated in accordance with the ideal gas law and the AC (volume percent of anesthetic compound required to produce negative righting reflex in 50 percent of the test mice, in five minutes and the LC (volume percent of anesthetic compound required to kill 50 percent of the test mice in ten minutes) were determined by graphic estimation according to the procedure described by Miller et al., Proc. Socy. Exper. Biol.

Med., vol. 57, pp. 261-4 (1944). The results, including the calculated inhalation margin of safety (LC AC are set forth in the following table in which the corresponding comparative data for chloroform, ether and halothane detennined in identical tests are similarly recorded.

It is apparent from the above data that l-bromo-l-chloro- 40 2,3,3-trifluoropropene is a potent anesthetic, has a low toxicity and, overall, has a better margin of safety than the three comparative general anesthetics in common use.

As many widely different embodiments of this invention can be made by the person skilled in the art without departing from the spirit and scope thereof, it is to be understood that this invention is not limited to the specific embodiments thereof except as defined in the appended claims.

What is claimed is:

1. A process for inducing anesthesia in warm-blooded, airbreathing animals comprising administering to said animal by inhalation an effective amount of for inducing anesthesia of CBrCl CF-CHF}.

UNITED STATES PATENT GFFEGE (ZERTEFEQA'EE Gt QOREQTWN Patent No. 3, 671, 645 Dated June 20 1972 1nventor(s) Bernard M. Regan It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the title, cancel "ANETHESIA' and insert --ANESTHESlA--.

At col. 1, line 7, the structural formula should appear as follows:

CBrCFCF-CHF At col. 2, line 15, after "6. 3" insert -liter--; at line 26,- cancel "LC 'AC and insert --LC- /AC at line 53 cancel "of", first instance. I

Signed and sealed this'30th day of January 1973.

(SEAL) Attest:

ROBERT GOTTSCHALK EDWARD M.FLETCHER,JR.

C ommiss'ioner of Patents Attesting Officer USCCMM-DC 60376-P69 a u.s. GOVERNMENT "mums ornc: 19a 0-366-838 FORM PO-1050 (10-69) 

